Post by Fanny on Sept 28, 2017 0:57:03 GMT -8
MASTERING THE GENNAKER, by Destiny Wescott
This tutorial will explain how to easily use your genn to achieve faster speeds with your Nacra using a AWA as low as 45. Whether if you just bought your Nacra or are well experienced sailing it, this tutorial will be of interest to you. As long as you already know the basics on how to sail and are familiar with how to control your Nacra as described in the manual that came with it, you should have no problem following along with this tutorial.
Quick reference for beginners:
AWA - Apparent Wind Angle
Genn - Gennaker
Sheet - Sheet Angle
-Attached here is a picture of me on my boat with brief descriptions of
the setting from the text display of the Nacra that we will be using to follow
along with the tutorial.
The first part of this tutorial will have you sailing faster speeds using your genn with a lower AWA then you have before, all in a matter of minutes. The second part of this tutorial will explain in further detail how you can push the limits of the genn for slightly faster speeds... for those of you that are determined to be the fastest on the water!
-------- PART 1 --------
This technique you will be learning to use with your genn, focuses on its use when the text display of your Nacra turns yellow and your sails flap in the wind....
"Oh no! I didn't just say that, did I? But yellow text and sails flapping are signs of trouble!"
Rest assured, with this technique you won't be in any trouble unless your text display turns RED. Thats when your genn will start flapping and the real trouble begins.
There are two things you will need to focus on, your Sheet Angle and AWA. To get you started were going to use a sheet angle of 37. The sheet can be set at other angles, but I find 37 is the most well rounded in reference to performance v.s. speed. I will discuss the use of other sheet angles in Part 2 of this tutorial, but to get you started use a sheet of 37 for Part 1 of this tutorial. The AWA's we will focus on when using a sheet of 37 range from 45 - 62. When your AWA is between 45 - 62, the color of your text display will be yellow. This is when you will want to set your Sheet to 37 and raise your genn. Go ahead and give it a try!
(I suggest using your ipad to set a racing wind with no variation or gusts, instead of using the default cruising wind. I find the AWA to be a little more stable with a racing wind, which is nice if you want to sail with the lower AWA's and not have to worry about it dropping too low all of a sudden.)
AWA SHEET
45-62 37
You will be able to sail much faster sailing with the genn this way verses sailing without the genn and a sheet angle half of your AWA. The fastest speeds that can be reached using the genn with this range of AWA's are with an AWA between 50-56. With a wind of 15 knots you can reach speeds up to 17.8 knots. There is a big increase of speed going from an AWA of 49 to 50. So if It doesn't take you off course, try to keep your AWA above 49 if possible. More about top speeds will be discussed in Part 2.
This is all you need to know to get you sailing faster then before. In Part 2 I will compare top speeds for the different AWA's in relation to different Sheet Angles, will compare how much faster the genn is v.s. without it, If and when you should change the sheet angle, and talk about the mysterious AWA of 44 with a sheet angle of 37; "Why is my text display some times yellow and some times red with 44?". Even if you prefer to just kick back and stick with one sheet angle, Part 2 will help you choose which sheet angle is best for you.
-------- PART 2 --------
Chances are your already sailing faster then ever before with the potential of lowering lap times of your favorite courses that would put your previous records too shame... Congrats!
Now lets see if we can improve your speed yet a little more... or at least find what the best sheet angle will be for you. I have sailed many speed tests using a wind of 15 knots to find the top speeds using the genn with different AWA's and sheet angles.
(note: these top speeds for each AWA was determined by maintaining that AWA long enough for any acceleration or deceleration from a previous AWA to cease. Because this is such a difficult task to do, my results might be off by 0.1 knots. I feel confident that most, if not all of them are accurate)
Posted in the following chart are the results. The left column lists the different AWA's I had tested with. The columns to the right of it list the top speeds for various sheet angles in relation to each of the different AWA's. There are three sheet angles I tested for top speeds while using the genn. I had also tested for top speeds without the use of the genn when the sheet angle is half of the AWA, for a comparison of just how much faster using the genn is. They are clearly marked for easy reference. For the three different sheet angles I have listed, I only tested for top speeds with AWA's in which the color of the text display for the Nacra was yellow. I also highlighted in red, the fastest top speed of each column. Take a moment to look them over... then I will point out a few interesting things about them to help you put it to good use.
As you can see from the chart, I have listed top speeds for only three different sheet angles. Other sheet angles can also be used, but I find these to be most effective.
The lowest sheet angle I ever suggest using is a sheet of 36, and only in extreme conditions. I will come back to when a good time to use a sheet of 36 may be. If anyone tells you to try using a sheet of 35, walk away and stop taking their advice. As it says in the manual for the Nacra:
"A main sheet setting of 35 degrees or lower will in effect render the gennaker useless."
I have taken the time to test out a sheet of 35 and can tell you it will actually slow you down. Your top speeds will be even slower then if you were not using the genn.
When looking at the chart you might notice that I have a top speed listed for a AWA of 44 with a sheet of 37, when in Part 1 of this tutorial I had you keep your AWA between 45-62. Sailing with a AWA of 44 can be very risky and I wanted everyone to get the hang of this without any problems.
Allow me to explain why a AWA of 44 won't always work. I have come to the conclusion that the scripts in the Nacra measure the degree of the AWA in smaller increments then the whole numbers that the text display shows us. We are shown whole numbers to make it easier to read while sailing.
You will notice if you have been sailing on a straight course for some length, if you don't steer the boat.... theres usually enough wind pressure on the sails to gradually change the heading of the boat, causing your AWA to slowly increase or decrease. Because the scripts will slowly increase or decrease the AWA in smaller units then whole numbers, an AWA of 44 may not always work. You will often find this to be the case with the cut off point for all sheet angles. Though I only find the cut off point for the AWA of 44 and a sheet of 37, to be low enough to try and make use of it. If I had to guess exactly at what point a AWA of 44 would change the text display from yellow to red, I would say it would be about at 44.2 degrees. Which if your not sailing with any variation or gusts and are able to sail a thin line, then you just might be able to sail with a AWA of 44 if you like to push the limits. At the very least, it makes sailing with a AWA of 45 a lot less risky, you will have more time to adjust your AWA back to a safer number if it were to drop down to a 44.
I suggest only sailing close to the cut off point of your AWA when your AWA is slowly increasing. If you just finished tacking, give it a moment for your AWA to level out and to stop decreasing.
Now may be a good time to discuss if a sheet of 36 is worth using. As you may have noticed from the chart, the lower the sheet, the lower the AWA it is effective with. But this advantage of a lower sheet angle comes with a slight cost. You will also have slightly slower top speeds for many of the AWA's. Overall, a sheet of 36 is to slow for me to even take the time to test for top speeds. However, I wouldn't completely rule it out as an option. If I'm sailing a course and it looks like I'm going to barely Not clear an obstacle, using a sheet of 36 can come in very handy to allow for a smaller AWA which just may save me from having to lower my genn.
The cut off point for a sheet of 38 is going to be with a AWA of 45... and for a sheet of 39, its going to be with a AWA of 46. I didn't bother testing for top speeds for them since the color of the display text turns red and the genn starts to flap much to quickly. Keep that in mind when sailing with a sheet of 38 or 39.
Them are the cut off points for at the top of the chart. The cut off points at the bottom of the chart, are where the color of the text display will change from yellow to green. There is no need to make any adjustments when your AWA goes beyond this point unless you want too. I didn't do any speed tests here since the boat will be planning which makes it difficult to keep a steady AWA. Keep in mind though, I was able to sail faster with a sheet of 37 and an AWA of 63-65 (text display green) then I had with a sheet of 39 with an AWA of 63-65 (text display yellow).
Can you use a higher sheet angle? Sure you can, but if you look at the direction the data from the chart is heading towards... you will notice that if you use too high of a sheet angle, you will have a very limited range of AWA's for it to be worth using. That and remembering when exactly to shift up or down between that many different sheet angles could be a challenge of its own.
Knowing what is the best sheet angle to use is going to be up to you. Keep in mind though, when sailing with variation and gusts... your AWA will increase and decrease much more frequent and in range. Which can make sailing with a higher sheet angle less desirable.
----------------------------
I hope this tutorial has been helpful to you. I look forward to seeing more Nacra's out on the water sailing at faster speeds:) If you have any questions, please feel free to IM me. If I"m away or busy racing, I will respond when I get the chance... just be sure to mention this tutorial or the Nacra so I don't mistaken you for a random IM.
Brought to you by,
Destiny Wescott
This tutorial will explain how to easily use your genn to achieve faster speeds with your Nacra using a AWA as low as 45. Whether if you just bought your Nacra or are well experienced sailing it, this tutorial will be of interest to you. As long as you already know the basics on how to sail and are familiar with how to control your Nacra as described in the manual that came with it, you should have no problem following along with this tutorial.
Quick reference for beginners:
AWA - Apparent Wind Angle
Genn - Gennaker
Sheet - Sheet Angle
-Attached here is a picture of me on my boat with brief descriptions of
the setting from the text display of the Nacra that we will be using to follow
along with the tutorial.
The first part of this tutorial will have you sailing faster speeds using your genn with a lower AWA then you have before, all in a matter of minutes. The second part of this tutorial will explain in further detail how you can push the limits of the genn for slightly faster speeds... for those of you that are determined to be the fastest on the water!
-------- PART 1 --------
This technique you will be learning to use with your genn, focuses on its use when the text display of your Nacra turns yellow and your sails flap in the wind....
"Oh no! I didn't just say that, did I? But yellow text and sails flapping are signs of trouble!"
Rest assured, with this technique you won't be in any trouble unless your text display turns RED. Thats when your genn will start flapping and the real trouble begins.
There are two things you will need to focus on, your Sheet Angle and AWA. To get you started were going to use a sheet angle of 37. The sheet can be set at other angles, but I find 37 is the most well rounded in reference to performance v.s. speed. I will discuss the use of other sheet angles in Part 2 of this tutorial, but to get you started use a sheet of 37 for Part 1 of this tutorial. The AWA's we will focus on when using a sheet of 37 range from 45 - 62. When your AWA is between 45 - 62, the color of your text display will be yellow. This is when you will want to set your Sheet to 37 and raise your genn. Go ahead and give it a try!
(I suggest using your ipad to set a racing wind with no variation or gusts, instead of using the default cruising wind. I find the AWA to be a little more stable with a racing wind, which is nice if you want to sail with the lower AWA's and not have to worry about it dropping too low all of a sudden.)
AWA SHEET
45-62 37
You will be able to sail much faster sailing with the genn this way verses sailing without the genn and a sheet angle half of your AWA. The fastest speeds that can be reached using the genn with this range of AWA's are with an AWA between 50-56. With a wind of 15 knots you can reach speeds up to 17.8 knots. There is a big increase of speed going from an AWA of 49 to 50. So if It doesn't take you off course, try to keep your AWA above 49 if possible. More about top speeds will be discussed in Part 2.
This is all you need to know to get you sailing faster then before. In Part 2 I will compare top speeds for the different AWA's in relation to different Sheet Angles, will compare how much faster the genn is v.s. without it, If and when you should change the sheet angle, and talk about the mysterious AWA of 44 with a sheet angle of 37; "Why is my text display some times yellow and some times red with 44?". Even if you prefer to just kick back and stick with one sheet angle, Part 2 will help you choose which sheet angle is best for you.
-------- PART 2 --------
Chances are your already sailing faster then ever before with the potential of lowering lap times of your favorite courses that would put your previous records too shame... Congrats!
Now lets see if we can improve your speed yet a little more... or at least find what the best sheet angle will be for you. I have sailed many speed tests using a wind of 15 knots to find the top speeds using the genn with different AWA's and sheet angles.
(note: these top speeds for each AWA was determined by maintaining that AWA long enough for any acceleration or deceleration from a previous AWA to cease. Because this is such a difficult task to do, my results might be off by 0.1 knots. I feel confident that most, if not all of them are accurate)
Posted in the following chart are the results. The left column lists the different AWA's I had tested with. The columns to the right of it list the top speeds for various sheet angles in relation to each of the different AWA's. There are three sheet angles I tested for top speeds while using the genn. I had also tested for top speeds without the use of the genn when the sheet angle is half of the AWA, for a comparison of just how much faster using the genn is. They are clearly marked for easy reference. For the three different sheet angles I have listed, I only tested for top speeds with AWA's in which the color of the text display for the Nacra was yellow. I also highlighted in red, the fastest top speed of each column. Take a moment to look them over... then I will point out a few interesting things about them to help you put it to good use.
As you can see from the chart, I have listed top speeds for only three different sheet angles. Other sheet angles can also be used, but I find these to be most effective.
The lowest sheet angle I ever suggest using is a sheet of 36, and only in extreme conditions. I will come back to when a good time to use a sheet of 36 may be. If anyone tells you to try using a sheet of 35, walk away and stop taking their advice. As it says in the manual for the Nacra:
"A main sheet setting of 35 degrees or lower will in effect render the gennaker useless."
I have taken the time to test out a sheet of 35 and can tell you it will actually slow you down. Your top speeds will be even slower then if you were not using the genn.
When looking at the chart you might notice that I have a top speed listed for a AWA of 44 with a sheet of 37, when in Part 1 of this tutorial I had you keep your AWA between 45-62. Sailing with a AWA of 44 can be very risky and I wanted everyone to get the hang of this without any problems.
Allow me to explain why a AWA of 44 won't always work. I have come to the conclusion that the scripts in the Nacra measure the degree of the AWA in smaller increments then the whole numbers that the text display shows us. We are shown whole numbers to make it easier to read while sailing.
You will notice if you have been sailing on a straight course for some length, if you don't steer the boat.... theres usually enough wind pressure on the sails to gradually change the heading of the boat, causing your AWA to slowly increase or decrease. Because the scripts will slowly increase or decrease the AWA in smaller units then whole numbers, an AWA of 44 may not always work. You will often find this to be the case with the cut off point for all sheet angles. Though I only find the cut off point for the AWA of 44 and a sheet of 37, to be low enough to try and make use of it. If I had to guess exactly at what point a AWA of 44 would change the text display from yellow to red, I would say it would be about at 44.2 degrees. Which if your not sailing with any variation or gusts and are able to sail a thin line, then you just might be able to sail with a AWA of 44 if you like to push the limits. At the very least, it makes sailing with a AWA of 45 a lot less risky, you will have more time to adjust your AWA back to a safer number if it were to drop down to a 44.
I suggest only sailing close to the cut off point of your AWA when your AWA is slowly increasing. If you just finished tacking, give it a moment for your AWA to level out and to stop decreasing.
Now may be a good time to discuss if a sheet of 36 is worth using. As you may have noticed from the chart, the lower the sheet, the lower the AWA it is effective with. But this advantage of a lower sheet angle comes with a slight cost. You will also have slightly slower top speeds for many of the AWA's. Overall, a sheet of 36 is to slow for me to even take the time to test for top speeds. However, I wouldn't completely rule it out as an option. If I'm sailing a course and it looks like I'm going to barely Not clear an obstacle, using a sheet of 36 can come in very handy to allow for a smaller AWA which just may save me from having to lower my genn.
The cut off point for a sheet of 38 is going to be with a AWA of 45... and for a sheet of 39, its going to be with a AWA of 46. I didn't bother testing for top speeds for them since the color of the display text turns red and the genn starts to flap much to quickly. Keep that in mind when sailing with a sheet of 38 or 39.
Them are the cut off points for at the top of the chart. The cut off points at the bottom of the chart, are where the color of the text display will change from yellow to green. There is no need to make any adjustments when your AWA goes beyond this point unless you want too. I didn't do any speed tests here since the boat will be planning which makes it difficult to keep a steady AWA. Keep in mind though, I was able to sail faster with a sheet of 37 and an AWA of 63-65 (text display green) then I had with a sheet of 39 with an AWA of 63-65 (text display yellow).
Can you use a higher sheet angle? Sure you can, but if you look at the direction the data from the chart is heading towards... you will notice that if you use too high of a sheet angle, you will have a very limited range of AWA's for it to be worth using. That and remembering when exactly to shift up or down between that many different sheet angles could be a challenge of its own.
Knowing what is the best sheet angle to use is going to be up to you. Keep in mind though, when sailing with variation and gusts... your AWA will increase and decrease much more frequent and in range. Which can make sailing with a higher sheet angle less desirable.
----------------------------
I hope this tutorial has been helpful to you. I look forward to seeing more Nacra's out on the water sailing at faster speeds:) If you have any questions, please feel free to IM me. If I"m away or busy racing, I will respond when I get the chance... just be sure to mention this tutorial or the Nacra so I don't mistaken you for a random IM.
Brought to you by,
Destiny Wescott
